Group processing is known that distributes predetermined processes to plural terminals (see, e.g., Japanese Laid-Open Patent Publication Nos. 2007-336360 and 2008-72711). When performing the group processing, for example, a data coherency process is performed with respect to resources shared by the plural terminals, whereby coherency among data (caches) retained by the terminals is established. In performing the data coherency process, for example, broadcast communication is used to transmit the data retained by one terminal to other terminals.
With conventional technologies described above, however, when there is a terminal that cannot immediately receive the data transmitted by the broadcast communication, the broadcast communication is difficult to complete and the data coherency process takes time. Consequently, a problem arises in that group processing cannot be performed efficiently.